AUSTIN - Attorney General Ken Paxton's criminal defense lawyers filed a motion Wednesday arguing the judge assigned to oversee his securities fraud trial is ineligible to oversee the case because his appointment was temporary.

Legal experts say the argument appears dubious as Paxton's legal team looks for ways to secure a new judge in a high-profile legal battle that could decide the political fate of the state's most embattled Republican.

"Big firms fight for every inch," said Edward Mallett, a Houston criminal defense lawyer. "I admire the lawyers for being scrappy."

The motion argues that any rulings District Judge George Gallagher has made in the attorney general's case since in 2017 should be "vacated and declared void," including his decision to move the trial out of Paxton's back yard of Collin County and into Harris County. The case should be reassigned to a new Collin County jurist who assumed office in January, according to the motion.

The filing is the latest attempt by Paxton's legal team to get rid of Gallagher, a Tarrant County judge appointed to oversee the case in 2015 after Collin County Judge Chris Oldner declared a conflict of interest presiding over the case.

'Plenary powers'

Paxton's legal team filed the motion with Judge Mary Murphy, the presiding judge of the First Administrative Judicial Region, arguing she had assigned Gallagher to her region until Dec. 31, 2016, which should render rulings he's made since then null and void.

She assigned Gallagher to hear cases in the region on July 29, 2015 to last "until the plenary power has expired or the undersigned Presiding Judge has terminated this assignment in writing, whichever occurs first."

"Plenary power" refers to a court's power to dispose of a matter before it, according to Black's Law Dictionary. That means Gallagher likely has the power to stay with the case until the end, regardless when his time in the judicial region expires, said Mallett, past president of the national, state and county association of criminal defense lawyers. He said the filing's lack of reference to case law likely reveals that Paxton's legal team is looking for creative ways to remove the judge without past precedent to back up their arguments.

"This is Texas: issues not clearly controlled by precedent are influenced by politics. The law is art and science combined," said Mallett.

Paxton's attorneys and special prosecutors assigned to the case are under a gag order and did not return calls for comment.

Paxton's legal team first tried to shed Gallagher from the case in April, hours after the judge ruled he would move the case out of Paxton's back yard of Collin County. Gallagher said before the ruling he worried about powerful influences in the county amid a series of lawsuits backed by Paxton's allies and campaign donors to defund special prosecutors.

Trial set for September

Paxton's attorneys refused to sign routine paperwork to retain the judge as the case moved to Harris County, although Gallagher said he expects to remain on the case. Paxton's legal team has since asked county clerk's office to assign them a new judge, but the county said it does not have that power.

Paxton faces two first-degree felony securities fraud charges for convincing colleagues and friends to invest in a North Texas tech company without saying he would make a commission. He faces a lesser charge of failing to register with the state as an investment advisor.

Andrea Zelinski is a state bureau reporter focusing on education, politics, social issues and the courts. She previously covered the Tennessee legislature and local education for the Nashville Scene where she was news editor. She also wrote for the Nashville Post, the now defunct Nashville City Paper and TNReport news service, covered the Illinois statehouse and reported for the Associated Press and Small Newspaper Group. A Chicago-area native, she has a master’s degree in Public Affairs Reporting from the University of Illinois at Springfield and earned her undergraduate degree at Northeastern Illinois University.